title: Degradation of β-conglycinin β-homotrimer by papain: independent occurrence of limited and extensive proteolysis.
abstract: Limited and extensive proteolysis occur when β-conglycinin β homo-trimer (β(3)-conglycinin) from soybeans is attacked by papain. Slow limited proteolysis is restricted to cleavage of β(3)-conglycinin polypeptides into subunit halves (N- and C-terminal domains) that are further slightly truncated. The kinetics of limited and extensive proteolyses analyzed separately indicates that the two processes occur independently from the very beginning of the reaction. In contrast, limited proteolysis of phaseolin from common beans has been found to be prerequisite for the onset of its extensive proteolysis. The dramatic distinction between the degradation patterns of β(3)-conglycinin and phaseolin, homologous storage 7S globulins, suggests the existence of intrinsic differences in their structures. This hypothesis is supported by comparative analysis of the accessibilities to the solvent of amino acid residues in phaseolin and β(3)-conglycinin structures, which indicated the relatively low packing density of the latter, resulting in enhanced susceptibility of it to extensive proteolysis.
authors.affiliation: Laboratory of Plant Biochemistry, Moldova State University.
authors.forename: Andrei D
authors.initials: AD
authors.lastname: Shutov
authors.forename: Angela S
authors.initials: AS
authors.lastname: Rudakova
authors.forename: Sergei V
authors.initials: SV
authors.lastname: Rudakov
authors.forename: Irina A
authors.initials: IA
authors.lastname: Kakhovskaya
authors.forename: Anna A
authors.initials: AA
authors.lastname: Schallau
authors.forename: Karl A
authors.initials: KA
authors.lastname: Wilson
authors.forename: Nobuyuki
authors.initials: N
authors.lastname: Maruyama
mesh_terms: D000595:Amino Acid Sequence; D052179:Antigens, Plant / Q000737:chemistry* / Q000378:metabolism*; D005916:Globulins / Q000737:chemistry* / Q000378:metabolism*; D006868:Hydrolysis; D007700:Kinetics; D008958:Models, Molecular; D008969:Molecular Sequence Data; D008970:Molecular Weight; D010206:Papain / Q000378:metabolism*; D010446:Peptide Fragments / Q000737:chemistry / Q000378:metabolism; D055503:Protein Multimerization; D020836:Protein Structure, Quaternary; D059748:Proteolysis; D055314:Seed Storage Proteins / Q000737:chemistry* / Q000378:metabolism*; D030262:Soybean Proteins / Q000737:chemistry* / Q000378:metabolism*; D013025:Glycine max; D013379:Substrate Specificity
chemical_list: D052179:Antigens, Plant; D005916:Globulins; D010446:Peptide Fragments; D055314:Seed Storage Proteins; D030262:Soybean Proteins; C013894:beta-conglycinin protein, Glycine max; D010206:Papain